Feeding device for molding machines



Feb- -f `.1. A. MULLER Erm.

FEEDING DEVICE FOR MOLDING MACHINES Filed Nov. 26, 193'7 lPatented Feb.` 11, `1941 GDEVICE FOR MOLDING MACHINES Johan A. Muller, Mansiield, and Warren R. Tucker and George M. Geiger, Mount Gilead, Ohio, assignors to The Hydraulic PressCorp. Inc., Wilmington, Del., a corporation of Delaware Application November 26, 1937, Serial No. 176,504

3 Claims.

This invention relates to feeding devices, and in particular, to devices for supplying molding material to plastic extrusion molding presses.

An object is to provide an injector for 'molding 5 material having an injector plunger with an expansible 'connection arranged between the injector plunger and theI means for reciprocating this plunger, so as to permit ,the position of the injector to be changed for different sizes of l dies by lengthening or shortening the plunger.

Another object is to provide anv injector for moldingmaterial having a reciprocable 'injector plunger connected to an operating member by means of an adjusting screw, and a spacing sleeve l permitting the effective length of the plunger to be adjusted for different sizes of dies.

Thegeneral organization of feeding mechanism disclosed herein forms no part of the present invention but is disclosed and claimed in the application `of Muller and Tucker, Serial No.

4142,674 filed May 14, 1937.

In lthe drawing:

Figure 1 is a central vertical section through the feeding device of this invention, showing the hydraulic plungers for advancing Ithe feeding and injecting mechanism, and also for operating the injector plunger. l

Figure 2 is an enlarged vertical section of a portion of Figure 1, showing the connecting device or adapter between the injector plunger and the injector piston rod, with an adapter spacer inserted therein.

Figure 3 is a view similar to Figure 2, butwith theadapter spacer removed.

Referring to the drawing in detail, Figure l shows a feeding device together with the hydraulic devices for actuating the feeding and injector units. Each feeding and injector unit consists of an injector, generally designated 5t, and a feeding device, generally designated' 65. Each 4feeding and injector unit (Figure 1) is mounted upon a slide 56, which engages a guide plate 5l bolted, as at 59, to the plate 59, mounted upon a suitable base. The injector 58 consists of a central cylinder 6| having radiating fins 62 engaging an'outer casing 63 so as to form a chamber therebetween for the circulation of a heating agent, such as heated oil. This oil enters by a passageway 69 in an insulating Wall 65,' and leaves by a similar passageway 66 (Figure 1). The injector cylinder 6| contains a bore 6l with' an enlargement 68 containing a spindle-shaped defiector 69, having passages i8 for the passage of the plastic material.

Beyond the enlargement .68 and the deflector 89 is a nozzle ii having an orice l2 in a rounded tip '13. The injector cylinder 8| is spaced by means of an insulation disc 'lli from a anged portion 'i5 of the feed casing 16. The latter is surrounded by a cylindrical Wall Tl, thereby pro (ci. zar-s2) viding a chamber 18, subdivided by annular fins 19 and having ports 88 and 8| for the admission and' discharge of a cooling uid. The purpose of this cooling fluid is to prevent the premature softening of the molding material before it reaches .the injector chamber 81, thereby preventing the clogging ofthe feeding mechanism.

Within the feed casing is a sleeve 82 having an aperture 83 communicating with an inclined 'feed bore 84, with a rotary feed screw 85 therein. A conical throat 86 admitsV molding material, in the form of small particles, to the feed bore 89 from the feed hopper 8l, supported in the`holder 88.

The feed screw 85 is connected to a shaft 89 mounted on anti-friction bearings 98, held in place by the retaining plate 9i. The shaft 89 is' connected by the pin 92 to the couplingv 93 on the output shaft 88 of the geared motor unit, generally designated 95. The latter consists of a motor 96 connected to areduction gear box 8l, by which .the speed of the motor is reduced to the slow speed necessary for operating the feed screw 65. The geared motor unit 95 is mounted upon a support A98, with a post 99 secured to the slide 56 by the bolts |88. A

The support 98 is provided with an Mangled portion |8i. to which the piston rod |82 is secured by means of the nuts |83 threaded thereon. Similarly, the feed casing 'i6 has a' downwardly extending post |88, bolted as at |85, to the slide 58 andconnected to the piston rod |86 by the nuts |81 threaded on the end thereof. The piston rods |82 and |86 terminate in piston heads |88 and |89, respectively, reciprocable in cylinder bores ||8 and At their opposite ends these cylinder bores are provided with passages ||2 and H3, also H8 and H5,` respectively, (Figure 1). Surrounding the piston rods |82 and |861 are the closure 'plates ||6, having packings ||1 compressed by glands ||8 for the prevention of leakage. -'Ihe closure plates ||6 are bolted, as at ||9, to the cylinder blocks |28 containing the cylinder bores 8 and A| l The cylinder bloc-k |28 also contains an injector cylinder bore |2|, with a piston head |22 mounted on a piston rod |23, the opposite end of which is provided with a threaded bore |28.

The piston rod |23 is connected to the injector plunger |25 by a coupling, generally designated |26. This coupling is arranged to permtthe distance between the injector plunger |26 and the piston rod |23 to be lengthened or shortened, according to the size of the dies which the device may be used to feed. For this purpose an adapter screw |2'i (Figures 2 and 3) is threaded into the threaded bore |25, and is provided with a head |28 with a T-slot |29. Between the end of the piston. rod |23 and the slotted head |28 is placed a split ring |38, the halves of which are held togetherby the cap screws |3|. Surrounding the slotted head |28 and the split ring '1| to the increased size of die.

| is a collar |32 for additionally retaining the various portions and holding them together. The injector plunger |25 is provided with a. iianged enlargement |33, with a T-shapedprojection |34 fitting into the slot |25. In order to make use of this coupling device |25, the injector plunger |25 is provided with an indexA marker |35, which exactly registers with the outer end of the sleeve 82 when the injector |35 again comes exactly at the outer end of the` sleeve 82, the split ring |30 being removed by removing the cap screws ist. The split ring |36 is then replaced by a shorter split ring, and the assembly clamped together again in the manner shown in- Figure 2. By supplying split rings is@ in various lengths, the apparatus can be adapted .Y to dies of varying sizes. When the split ring |35 isentirely removed and the coupling |25 reassembled, the apparatus is adjusted for the maximum permissible size of die, and its appearance is then as shown in Figure 3. The cylinder bore |2| for the injector piston head |22 is closed by an end plate |35, with a port '|31 therein. The opposite end of the cylinder bore |2| is provided with a port |38. j

Mounted onthe-'post e@ is a supporting plate |39, upon which a pair of limit switches Maand mi is adjustably. mounted and adapted to be operated by engagement with the collar |32. Similarly, the'slide 55 carries a limit switch |52, adjustably mounted thereon and adapted to be engaged by a collar |53 on the piston rod |06. The limit switches |50 and |4l| controll the action of the geared motor unit 95 for operating the feed screw 05. 'Ihe limit switch |52, however, controls the energlzation of solenoids connected to valve rods for shifting the injector operating valves.

In the operation of the device, pressure iiuid is supplied to the cylinder bores H5, causing the pistons |08 and |09 thereof to move inwardly, thereby shifting the feeding and injector unit into engagement with the die which the device is to feed. As the piston rod |06 pushes the feeding and injector unit into engagement with this die (not shown) the collar |03 engages and closes the limit switch |42 (Figure l), therebyenergizing the electrical devices which supply pressure fluid to the injector cylinder bore |2l.

` the cavities of the die.

"in the injector chamber 61, is then pushed past the deector 69 and through the orice '|2 into 'I'he limit switches |40 and |4| come into play at this point to operate Y, the geared motor unit 95 so as to cause the feed screw 85 to rotate and feed more of the particles of molding material from the feed chamber -84 into the injector chamber 6l. These limit switches and. IM are connected to .an electrical circuit, forming no part of the' present invention, but disclosed and claimed in the copending application of Ernst and Lawyer, Ser. No. 138,904, led April 26, 1937. v

By the operation of these limit switches m0 and It! the feed screw 85 is caused to feed a slight excess of material into the injector charnber 61 so that an adequate amount of material is always present in the chamber. As a surplus amount of material collects therein the injector plunger |25 is incapable of executing a complete injection stroke, hence, the collar |32 is temporarily incapable of engaging and actuating the limit switch |4|. The electrical circuit then remains deenergized, and the feed screw 85 remains inactive and skipsV a cycle while the injector plunger |25 executes another injection stroke and clears the injector chamber Si of the surplus material.

After the material has been allowed to cool in the die for av sufficient length of time the injector operating valves are shifted by the oper- ,ator so that pressure iluid enters the port |38 in the injector operating cylinder bore l2 thereby returning the injector operating piston |22 to its starting position. Pressure fluid is then admitted into the passages ||3 and H5 at the ends of the cylinder bores |||l and Hi, causing the pistons nos and los to shift the feeding and injector unit out of engagement with the die. The feeding and injector unit thereby returns to its starting position, ready for the execution of another feeding and injection cycle.

It will'be understood that we desire to comprehend within this invention lsuch modifications as come within the scope of the claims and the invention.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. In a device for adjustably coupling two movable members, an adjusting screw threadedly engaging one of said members and having a head with a T slot, the other member having a T projection Ailtting into said T slot, and a spacing sleeve surrounding said adjusting screw and disposed between said screw head and said threadedly engaged member.

2. In va device for adjustably coupling two movable members, an adjusting screw threadedly engaging one of'said members and having a head with a T slot, the other member' having a. T prof jection fitting into said T slot, a split spacing sleeve surrounding said adjusting screw and disposed between said screw head and said threadedly engaged member, and means for clamping the split portions of said sleeve together.

3. In a device for adjustably coupling two movable members, an adjusting screw threadedly engaging one of said members and having a head with a T slot, the other member having at one end a T projection fitting into said T slot, a split spacing sleeve surrounding said adjusting screw and disposed between said screw head and said threadedly engaged member for adjustably positioning one'of said members relatively to the other member, and -a retaining element surroundingsaid T projection and said screw head.

JOHAN A.V MULLER. WARREN R. TUCKER. GEORGE M. GEIGER. 

